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		<title xmlns:dc="http://purl.org/dc/terms/" property="dc:title">check.rdfa: Frequently Asked Questions</title>
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						<h1>check<span class="space"> </span><span class="r">rdfa</span></h1>
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<h2>Frequently Asked Questions</h2>

<h3>What does this service do?</h3>
	
<p>
	It checks your web page for <a href="http://www.w3.org/TR/rdfa-syntax/">RDFa</a>
	and displays any data found there. It also compares your data against the published
	recommendations from major consumers/users of RDFa data, to see how well your
	data matches their requirements.
</p>

<p>
	If your page doesn't raise any errors or warnings, it doesn't mean that your data is
	perfect&nbsp;&#8212; it just means that your errors may have been too ingenious
	for an automated tool to detect!!
</p>

<h3>Your service says my page is fine, but Google/Facebook/whatever can't see my data!</h3>

<p>
	Some services may have accidental or intentional deviations from the RDFa 
	standard in their parsers. This service does not attempt to replicate such bugs;
	nor can it, because I don't have insider information about how Google/Facebook/whatever
	parses RDFa.
</p>

<p>
	This service simply parses RDFa according to the W3C recommendations and
	compares the end result to the schemas accepted by major consumers.
</p>

<h3>What's all this "widget://" stuff?</h3>

<p>
	RDFa allows authors to include relative links in their HTML, like <code>&lt;a rel="next"
	href="page2">next&lt;/a></code>. If you use the file upload or code pasting facilities on
	this RDFa checker, then, for the purposes of resolving relative links, the service assumes that
	your document's base URL is something like <code>widget://blahblahblah.rdfa/self</code>
	in the absence of evidence to the contrary.
</p>

<p>
	If you're checking a web page by typing in its address or clicking on a link, then you should
	never see this stuff.
</p>

<h3>My page used to have no errors, but now it has lots!</h3>

<p>That's because we're adding extra checks all the time!</p>

<h3>How can I stop you checking my page?</h3>

<p>This service respects <a href="http://www.robotstxt.org/"
>the Robots Exclusion Standard (robots.txt)</a>, with a
User-Agent name of "check.rdfa".</p>

<p>Alternatively, you could filter HTTP requests containing
an HTTP User-Agent request header beginning with "check.rdfa".</p>

<h3>Can't you ignore my <tt style="font-size:90%">robots.txt</tt> file?</h3>

<p>No, but you can add this to it:</p>

<pre>    User-agent: check.rdfa
    Disallow:</pre>

<p>(i.e. disallow nothing - allow everything)</p>

<h3>Why doesn't the checker output valid XHTML?</h3>

<p>This service outputs valid XHTML+RDFa 1.1 and HTML5+RDFa. Most
pages content-negotiate between the two. HTML5+RDFa is currently
only a draft specification and is not yet supported by the W3C
validator, which is why you may see some validation warnings if
you try to validate check.rdfa.info pages.</p>

<h3>Is there an API?</h3>

<p>The checker can output data in JSON, YAML or <code>eval</code>-uable
Perl. You can either add a parameter to the request along the
lines of <tt>format=json</tt>, <tt>format=yaml</tt> or <tt>format=pl</tt>
or include <tt>application/json</tt>, <tt>text/x-yaml</tt> or
<tt>text/x-perl</tt> in the request's HTTP Accept header.</p>

<p>There's also support for PHP's <code>serialize</code>/<code>unserialize</code>
format, but this is broken due to a <a href="https://rt.cpan.org/Ticket/Display.html?id=58047"
>known bug</a> in a third-party library.</p>

<p>For completeness, <tt>format=html</tt> and <tt>format=xhtml</tt>
work; as do the media types <tt>text/html</tt> and <tt>application/xhtml+xml</tt>.</p>

<h3>&lt;insert some sort of question about HTTP Referer&gt;</h3>

<p>Yes, <a href="http://check.rdfa.info/check/referer"
>http://check.rdfa.info/check/referer</a> works how you want it to.</p>

<h3>What software powers this service?</h3>

<p>Perl. Here's a page listing the key Perl modules used along with which
<a href="/versions.cgi">version</a> is currently installled on the server.</p>

<h3>When will you support Microdata/Microformats?</h3>

<p>Never.</p>

<p>The aim of this tool is to check RDFa, and check it well. Adding support
for other formats would distract from that aim.</p>

<p>The Perl modules underlying this site are available on CPAN. It would not
be rocket science to pull out the RDFa parser and plug in a different
parser instead. (And indeed, I have written suitable Microformat and
Microdata parsers which are available on CPAN too.)</p>

<h3>Where can report bugs?</h3>

<p>Preferably via the <a href="http://code.google.com/p/check-rdfa/issues/list">Google
Code project</a>, though if you'd rather not make the details of your pages public,
you can <a href="http://tobyinkster.co.uk/">contact me</a>.</p>

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						<h6>RDFa Links</h6>
						<ul class="flist">
							<li><a href="http://www.w3.org/TR/rdfa-syntax/">XHTML+RDFa 1.0 Recommendation</a></li>
							<li><a href="http://www.w3.org/TR/rdfa-core/">RDFa Core 1.1 Draft</a></li>
							<li><a href="http://www.w3.org/TR/xhtml-rdfa/">XHTML+RDFa 1.1 Draft</a></li>
							<li><a href="http://www.w3.org/TR/rdfa-in-html/">HTML+RDFa Draft</a></li>
							<li><a href="http://www.w3.org/TR/xhtml-rdfa-primer/">RDFa Primer</a></li>
							<li><a href="http://rdfa.info/">rdfa.info</a></li>
						</ul>
					</div>
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						<h6>Service Links</h6>
						<ul class="flist">
							<li><a href="http://schema.org/">Schema.org</a></li>
							<li><a href="http://ogp.me/">Open Graph Protocol</a></li>
							<li><a href="http://www.w3.org/Submission/ccREL/">ccREL</a></li>
							<li><a href="http://www.google.com/support/webmasters/bin/answer.py?hl=en&amp;answer=99170">Google Rich Snippets</a></li>
						</ul>
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						<h6>Colophon</h6>
						<p xmlns:foaf="http://xmlns.com/foaf/0.1/" rel="foaf:maker"
						rev="foaf:made">Programming by <a about="http://tobyinkster.co.uk/#i"
						typeof="foaf:Person" rel="foaf:homepage" href="http://tobyinkster.co.uk/"
						property="foaf:name">Toby Inkster</a>.</p>
						<p>Hosting donated by <a href="http://melvincarvalho.com/"
						>Melvin Carvalho</a> and domain name supplied by <a
						href="http://creativecommons.org/">Creative Commons</a>.</p>
						<p>Most icons taken from <a href="http://www.famfamfam.com/lab/icons/silk/"
						>FamFamFam Silk</a>.</p>
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